The renal metabolism of beta2 microglobulin (B2M) will be evaluated in patients with various types of renal disease and carcinoma. In addition, experimental animal studies will be conducted. Dogs will be used to study the renal handling of B2M as affected by variations in renal blood flow, glomerular filtration rate and tubular metabolism under controlled conditions. The relationship of the filtered load of B2M to urinary excretion will be measured in patients with various renal diseases and carcinoma. Multiple large and small proteins will be measured, including IgA, IgG, IgM, lysozyme and B2M to determine the relative filterability of B2M with various disorders of glomerular permeability and tubular metabolism. The methods to be used will be those of standard immunologic, immunodiffusion and radioactive immunoassays for those proteins listed above, with the exception of lysozyme where the lysoplate method of Osserman will be utilized. The animal studies will be conducted as acute experiments using dogs with continuous steady-state perfusion experiments, evaluating the variations on renal blood flow, glomerular filtration rate and filtration fraction induced by various drugs and physiologic alterations. Variation in B2M isoprotein excretion in the urine will be evaluated, particularly in patients with various types of carcinoma. The standard isoelectric focusing techniques will be applied for evaluation of serum and urinary isoprotein measurements.